The present invention relates to encapsulation machines and, more particularly, to soft encapsulation machines which make soft gelatin and non-gelatin capsules.
Typical soft encapsulation machines form at least two flexible gelatin sheets or ribbons by cooling molten gelatin on separate drums then lubricating and guiding the sheets into communication with each other over co-acting dies while simultaneously dispensing a desired quantity of fill material between the sheets in synch with cavities in the outer surfaces of the dies to produce soft capsules. The encapsulation machines typically utilize gearing to control the relative rotations of the various components and fill mechanisms to synchronize the operation of these various components. The synchronization of these various components, however, can vary depending upon a variety of factors, such as the particular dies used, the number of cavities and the size of the cavities on the dies, and the type of material used to form the sheets. To change the synchronization of the various components, mechanical gears are required to be changed to obtain the desired ratios and synchronization of these components. The changing of gears, however, is time intensive. Additionally, the use of mechanical gears provides finite gear ratios which limit the synchronization of the various components to the mechanical gears that are available. Thus, it would be advantageous to provide a capsule machine wherein the synchronization and rates at which the various components operate can be altered without the necessity of changing gears. Additionally, it would be advantageous if the synchronization between the various components can be infinite to thereby allow more precise synchronization between the various components. It would also be advantageous to allow various components, such as the fill mechanism, to be adjusted independently of the other components while the machine is running to allow for adjustments of the timing of fill material inserted into each of the soft capsules.
During the operation of the capsule making machine, the contact between the adjacent dies can be adjusted by the operator of the capsule making machine. Typically, the operator is able to move one of the dies closer to the other die so that the pressure or force exerted on the sheets passing between the adjacent dies can be adjusted. Such adjustments, typically are mechanical adjustments made by fluid actuators, such as pneumatic cylinders. The operator is able to adjust the pneumatic pressure thereby altering the force the dies exert on one another and on the sheets. This adjustability allows an operator to customize the pressure to ensure that quality soft capsules are produced. However, the dies are susceptible to premature failure and/or wear when the pressure or force between the two dies is more than that required to produce acceptable soft capsules. Thus, it would be advantageous to monitor/record the pressure applied to the dies so that quality capsules are produced without inducing excessive wear or premature wear on the dies.
A material fill mechanism is used to supply the fill material that is encapsulated within the soft capsules. When the fill material is a liquid, such as a liquid medication or dye for a paint ball capsule, the fill mechanism includes a plurality of positive displacement plunger-type pumps that are arranged in a housing above the dies. The plunger-type pumps are positioned on a yoke that moves linearly in a reciprocating motion to allow the plunger-type pump to fill with the liquid fill material on one stroke and subsequently discharge the liquid fill material on the other stroke. A valving arrangement between opposing pumps is utilized to control the discharge and filling of the pumps. The valve arrangement includes a sliding member that moves linearly back and forth in a direction generally perpendicular to the linear motion of the yoke. The discharge of the liquid fill material into the sheets as they are passing through the dies is coordinated with the operation of the dies to insure that the timing of the injection of the liquid fill material is synchronized with the cavities on the dies. Typically, this synchronization has been performed through the use of mechanical gears that link the timing of the stroke to the rotation of the dies. Thus, in order to adjust the synchronization a mechanical gear change is required which is time consuming. Additionally, the timing is limited to a finite number of gear ratios as determined by the gears that are available. Thus, it would be advantageous to provide a fill mechanism that is synchronized with the dies without the use of a mechanical linkage. Additionally, it would be advantageous if such synchronization could be adjusted during operation of the encapsulation machine to fine tune the synchronization and the production of capsules.
The sliding member of the valving mechanism requires lubrication. Typically, the lubrication is provided by a lubricating pump with its own separate drive. However, the use of a separate drive to operate the lubricating pump adds additional complexity and components to the capsule machine. Thus, it would be advantageous if a motion of the slide member and/or the yoke could be utilized to drive the lubrication pump.
The pumps are typically contained within a housing that is filled with a lubricating oil that is used to lubricate the sliding member. The pumps, however, can leak around their seals and contaminate the lubricating oil with the leaking fill material. Contamination of the oil requires a time consuming and possibly difficult clean up and can cause the lubricating oil to not perform as designed thereby increasing the wear on the sliding surfaces and decreasing the life span of the sliding surfaces. Thus, it would be advantageous to capture any fill material that leaks from the pumps and deter or prevent the liquid fill material from contaminating the lubricating oil within the pump housing.
The pumps are typically driven by a drive mechanism that is also located within the pump housing. Because the drive mechanism is located in the pump housing, it is possible for liquid fill material that leaks from the pumps to contaminate not only the lubrication oil but also the drive mechanism. When switching from one fill material to another, the pump and all of the components in the pump housing are required to be thoroughly cleaned to remove all contamination. The locating of the drive mechanism within the pump housing provides additional components that must also be cleaned when changing the fill material. Thus, it would be advantageous to separate the drive mechanism from the pump housing to reduce the components that are required to be cleaned when changing fill material.
The soft capsules produced by the encapsulation machine are transported from the encapsulation machine to a dryer to additionally dry the soft capsules and to make them into final form. The soft capsules are transported from the encapsulation machine to the dryer by a conveyor that extends along the front of the encapsulation machine. The conveyor can be contaminated by the fill material during operation of the encapsulation machine. When it is desired to switch the product being produced on the encapsulation machine, the conveyor must be removed from the encapsulation machine and cleaned to remove any contaminates thereon. The conveyor is driven by a motor that is attached to the conveyor. When it is necessary to remove the conveyor for cleaning, the motor must also be taken with the conveyor which makes it more difficult to remove and transport the conveyor and requires additional time to disconnect the motor from the encapsulation machine. Thus, it would be advantageous to provide a conveyor that can be easily and quickly disconnected from the motor and removed from the encapsulation machine without the motor. The present invention provides an encapsulation machine that overcomes the above-described disadvantages of typical encapsulation machines.
An encapsulation according to the principles of the present invention utilizes servomotors to drive various components of the encapsulation machine thereby eliminating the need for mechanical gearing to synchronize these components. The eliminating of the mechanical gearing simplifies the changeover of products, reduces cost, and also promotes easier fine tuning of operation of the encapsulation machine to produce capsules.
In another aspect of the present invention, the servomotors are controlled by a programmable controller that uses a serial communication ring to communicate with these components. The use of a serial communication ring facilitates the controlling of these components while minimizing the complexity of the control system. A further aspect of the present invention provides a controller with a virtual gear to which servo-driven components are keyed. Programmed relationships are used to control and coordinate the operation of the servo-driven components. This programming is advantageous in that it allows infinite numerical relationships to be programmed between the servo-driven components and the virtual gear. The use of the virtual gear is also advantageous in that a relationship between any servo-driven component and another servo-driven component can be established and easily modified through their relationships to the virtual gear.
The controller also enables the relationship between the servo-driven components and the virtual gear to be changed on-line or during production of the capsules to fine tune the operation of the encapsulation machine. This is advantageous in that no gearing changes are needed to make adjustments to the operation of the encapsulation machine. The controller also controls the operation of other non-servo-driven components. To control the non-servo-driven components, relationships between these non-servo-driven components and the virtual gear or other operating parameters or conditions of the encapsulation machine are programmed into the controller. The controller then uses these programmed relationships to coordinate and control the operation of these non-servo-driven components. (This is advantageous in that an adjustment in one of the components, such as the die rolls, allows the controller to automatically adjust the operation of the other components based upon these programmed relationships.) In yet another aspect of the present invention, the controller also enables the monitoring and recording of the various operational parameters of the encapsulation machine. The ability to monitor and record these operational parameters is advantageous in that it can facilitate the troubleshooting of the encapsulation machine and/or monitor changes an operator of the machine is implementing during production.
An encapsulation machine according to the principles of the present invention utilizing a control system that allows programmed relationships between components of the system to be selectively engaged and disengaged and altered is provided in still another aspect of the present invention. The ability to select whether the programmed relationships are implemented or not implemented is advantageous in that it allows the programmed relationships to be suspended so that troubleshooting can occur. Additionally, the ability to adjust the programmed relationships during operation of the machine is advantageous in that it easily allows the determination of ideal operating parameters for new fill material or new products being produced therein without requiring gear changes or alterations to the mechanical linkages during the establishment of operating parameters.
In another aspect of the present invention an encapsulation machine according to the principles of the present invention utilizes separate drive and pump housings that contain a respective drive mechanism and a pump assembly. The separation of the drive mechanism and pump assembly within different housings is advantageous in that if the pump assembly leaks fill material, the fill material does not contaminate the drive mechanism and drive housing, thus, enabling a simpler changeover between fill material by requiring less components to be cleaned. Additionally, in a further aspect of the present invention the pump assembly utilizes a tray beneath the pump assembly to capture fill material that may leak from the pumps and deters that fill material from contaminating lubricant within the pump housing.
Another aspect of the present invention includes an encapsulation machine according to the principles of the present invention which uses the motion of the pump assembly to drive a lubricating pump supplying a lubricating fluid thereto. The use of the motion of the pump assembly to drive a lubricating pump is advantageous in that it eliminates the need for a separate drive for a lubricating pump.
Another aspect of the present invention includes an encapsulation machine according to the principles of the present invention which uses a conveyor that can be quickly and easily decoupled from a motor driving the conveyor. The quick coupling and decoupling of the conveyor is advantageous in that it allows the conveyor to be easily and quickly removed from the encapsulation machine for cleaning without the necessity of taking a cumbersome motor with the conveyor.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.